Conventionally, mobile communication such as long term evolution (LTE) specified by the Third Generation Partnership Project (3GPP) is known (see, e.g., 3GPP TS36.300 V12.5.0, March 2015; 3GPP TS36.304 V12.4.0, March 2015; 3GPP TS36.211 V12.5.0, March 2015; 3GPP TS36.212 V12.4.0, March 2015; 3GPP TS36.213 V12.5.0, March 2015; 3GPP TS36.321 V12.5.0, March 2015; 3GPP TS36.322 V12.2.0, March 2015; 3GPP TS36.323 V12.3.0, March 2015; 3GPP TS36.331 V12.5.0, March 2015; 3GPP TS36.413 V12.5.0, March 2015; 3GPP TS36.423 V12.5.0, March 2015; 3GPP TS36.425 V12.1.0, March 2015; 3GPP TR36.842 V12.0.0, December 2013; 3GPP RP-150491, March 2015; 3GPP TS25.304 V12.5.0, March 2015). According to a known technique, a selection probability or priority is configured for each cell formed by a base station and the load is thereby distributed among the cells (see, e.g., 3GPP R2-142495, May 2014 and 3GPP R2-142530, May 2014).
According to another known technique, a base station informs a mobile station of a selection probability for the mobile station to select a pre-selected cell to be accessed when the mobile station transitions from an idle state to an active state, and the mobile station selects the pre-selected cell based on selection information and performs line configuration (see, e.g., WO 2008/023609).
According to another known technique, a base station operating plural cells each having a predetermined bandwidth measures the traffic state in each of the cells, determines a cell to which a mobile station is to be moved, based on the measured traffic state, and notifies the mobile station of the determined cell by using a paging channel (see, e.g., WO 2008/023611).